Nakasumi is the head of a company that makes toys and the fastest video game system on the market, the Z-board. Nakasumi designs the toys himself, most notably the Z-boy mascot. Nakasumi is known for speaking in whispers, and always has his translator Kyoko Yoshiko by his side to aid him. Kim Possible helped Nakasumi after Dr. Drakken stole his video game factory to build a giant robot. Kim would help him a second time in So the Drama when Shego attempted to kidnap him.